Crop Talk

[Jim Meade / Iowa City]

To me, this is a fascintating message on why the '12 yields were so good in spite of a drought as bad as '88.  It's simple - you follow the water.  Read this and see why we can't count on genetics and other modern conditions to let us dodge the bullet as we did.

"Most areas had soils that were fully recharged in the spring of 2012, with soils at field capacity all the way down to the water table. This allowed the roots to grow down to the 4-5 foot depth. With the dry weather in the summer, the water tables dropped, allowing the roots to continue growing down to the water table. Some corn roots were measured to a depth of 9 feet this past summer. Yields would have been much lower if this had not occurred. This is part of the reason that the impact of the 1988 drought was more severe, since we started 1988 with the subsoil moisture levels only half full. There was likely a foot or two of soil (from 3 to 5 foot depth) with very little or no moisture in the spring of 1988 because of the dry weather the previous year. This limited the root growth in 1988. I’m sure plant genetics also played a big role in the corn yields being better than expected this year."

The source of this is:

CROP UPDATE 11/16/2012
Iowa State University Extension Information for Southeast Iowa
By Jim Fawcett, ISU Extension Field Agronomist
3109 Old HWY 218 South
Iowa City, IA 52246
319-337-2145